WASHINGTON (CNN) -- A leading Republican senator said Sunday that President Bush's pick for U.N. ambassador has his vote "at this point," but added that he was troubled by criticism of the nominee.

The Senate Foreign Relations Committee is scheduled to vote Tuesday on the nomination of John Bolton to represent Washington at the United Nations.

Sen. Chuck Hagel, R-Nebraska, told CNN's "Late Edition with Wolf Blitzer" that he will support Bolton "if there's nothing more that comes out."

"I have been troubled with more and more allegations, revelations, coming about his style, his method of operation," said Hagel, the committee's second-ranking Republican.

"We need a uniter. We need a builder. We need someone who will reach out to our friends and our allies at the United Nations," Hagel said. "No question the United Nations needs reform. It badly needs reform. But we need someone who will go up there and develop confidence with the other ambassadors."

During confirmation hearings last week, senators heard allegations that Bolton tried to intimidate or have fired intelligence analysts who disagreed with him. Carl Ford, the State Department's former assistant secretary of state for intelligence and research, called Bolton "a serial abuser" and "a quintessential kiss-up, kick-down sort of guy." (Full story)

Bolton, the undersecretary of state for arms control, said one analyst had acted inappropriately by criticizing him behind his back. He told senators he did not want the man punished, but he did tell the man's supervisor that he had lost trust in him.

The committee was scheduled to vote on the nomination last Thursday, but Democrats delayed it to review additional materials related to Bolton's nomination. Those materials included recently declassified State Department documents and transcripts of interviews that committee staff members held with individuals thought to have knowledge of similar allegations, including one involving an analyst who now works for Hagel through a Capitol Hill fellowship. (Full story)

Hagel said the allegations are part of "a disturbing pattern of things that have come out about Bolton's management style."

"We cannot have that at the United Nations," he said. "That should not be anywhere in our government. If there's disagreement, there's disagreement. But to intimidate or to bully people is something that is not what we want in our government, especially at the very senior, responsible, high-level positions."

Republicans call Bolton a foreign policy realist who will help push U.S. calls for "reform" at the world body. Sen. Richard Lugar, the Foreign Relations Committee's chairman, said he expects Bolton to win confirmation.

"I do not believe that the judgments of members of the committee, even if there are additional facts or persons coming forward, are likely to change," Lugar, R-Indiana, told "Fox News Sunday."

But Democrats have criticized Bolton's handling of the diplomatic standoffs with North Korea and Iran over their nuclear programs and his previous public dismissals of the United Nations. Sen. Joseph Biden, the committee's ranking Democrat, told Fox that Bolton would lack credibility in the job.

"What happens when our ambassador has to stand up and make the case on intelligence relating to Iraq and North Korea?" asked Biden, D-Delaware. "Do you think John Bolton is going to be believed? And do you think it matters? I think it matters a great deal."

If confirmed, Bolton, 56, would replace John Danforth as head of the U.S. mission in New York. Anne Patterson, a career foreign service officer, has been acting ambassador since January, when Danforth departed.

Friday, the State Department released a package of letters supporting Bolton's nomination, including the endorsements of former Republican secretaries of state James Baker, Lawrence Eagleburger, Alexander Haig, Henry Kissinger and George Shultz.

Other former diplomats, including some Republicans, have written to the committee to urge the nomination's defeat.

And even some supporters have been lukewarm. Kissinger told CNN on Sunday that, "Not every aspect of John Bolton is something that I'm enthusiastic about." But he said Bolton had written "some extremely thoughtful pieces" on the international war crimes tribunal, which the United States has refused to join, and the doctrine of "universal jurisdiction," which asserts that any country can prosecute suspected war criminals.

"I believe -- and certainly from everything I've been told about him -- that he's an honorable enough man so that he will carry out his assignment with ability and with care," Kissinger said.

Zbigniew Brzezinski, who served as national security adviser in the Carter administration, said he did not consider Bolton a good choice, but he added, "Maybe we're better off with him sitting in New York at the U.N. than with him having an important post either in the State Department or in the National Security Council in the White House, actually shaping American policy."